Painting of Arc Sprayed Zinc Coatings with Water-Based Paints

Abstract

Hot dip galvanized zinc coatings on steel structures are known to have superior atmospheric corrosion resistance properties compared to painted structures. However, the zinc coating can not be applied by this method on large steel structures. The protection of large steel structures against atmospheric corrosion is traditionally done by painting. The environmental pressure to eliminate solvent based paints has forced the painting contractors to move towards water based paints or completely rethink the coating process. One solution to this problem is to use arc sprayed zinc as the "primer" and water based paints as a sealer and a top coat. The research and field tests conducted and supervised by VTT has produced promising results that are described in the paper. The possibility to apply water based paints directly over the arc sprayed zinc is discussed and results of field and laboratory tests are given. The economic aspects of both water based and traditional paint systems over the arc sprayed zinc are discussed in the paper.